Projectile and barrel for gun type perforators



C. C. COLE Nov. 18, 1941.

PROJECTILE AND BARREL FOR GUN TYPE PERFORATORS Filed Aug. '7, 1939 INVENTOR.

' conductor I.

Patented Nov.- 18, 1941 PROJECTILE AND BARREL FOB GUN ms PEBFOBATOES Cawthern 0. Cole, Whittier, Calif. Application August I, 1939, Serial No. 288,853

14 Claims.

My invention relates to a projectile and'barrel for gun perforators such as are used for perforating casing in place in well bores. Among the objects of the invention are the following:

First, to provide a projectile having an explosive receiving chamber wherein an explosion can occur and also having an explosive pressure delaying member whereby with projectile positioned in a gun barrel bore explosion pressure inside of the projectile will reach a high value before being suddenly released into the gun barrel.

Second, to provide a projectile particularly adapted for efilcient use in the necessarily short gun barrel of the usual gun perforator.

Third, to provide a projectile. which is readily loaded and which does not require a separate explosive containing cartridge.

Fourth, to provide a projectile having a novelly constructed pressure retarding and releasing means.

Fifth, to provide a projectile and gun barrel of extremely simple construction for use in gun type casing perforators.

Sixth, to provide a projectile for a gun perforator having a structure characterized by a rupturable explosive receiving shell.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the drawing, wherein for purposes of illustration, is shown a preferred embodiment of my invention:

Fig. 1 shows a gun barrel body in transverse section with my projectile in elevation.

Fig. 2 is a longitudinal sectional view of the projectile of my invention.

Fig. 3 is another form of the projectile of my invention shown partly in longitudinal section and partly in elevation.

As illustrated in Fig. 2, he projectile comprises a penetrating end or nose 3, threadably attached to a tubular portion ti and a shear plate 5 threadably engaging by means of rim I8 and closing the other end of said tubular portion. The numeral 6 designates an electric fuse wire attached at one end to tubular portion i and at its other end to a conductor I passing through an insulating bushing 25.

Referring to Fig. 1, the projectile 8 as above described is shown in position in the gun barrel 9. A flat spring in makes yieldable contact with An electrical conductor H extending through an insulating bushing I2 provides a connection between spring I and electric cable I3. A counter bore I4 provides a shoulder 2| serving as a seat for sealing plate I5 which is retained in place by a ring nut l5, providing sockets in its outer face adapted to accommodate a spanner wrench, threadably engaging gun body II.

In the operation of my invention chamber 29 is packed with explosive and with fuse wire 6 and shear plate [8-5 in place the projectile is positioned in gun bore 9.- Sealing plate I5, which is of any easily piercable material such as copper, is seated against shoulder 2| and there retained by ring nut I6.. It will be noted that the sealing plate bears against the end of the projectile and ensures that conductor I is in electrical contact with spring Ill. Electric cable I3 leads to a controlled source of.e1ectric energy by way of insulated bore -22 and conducts an electric current to effect the ignition of the charge of explosive by against the barrel means of the igniter wire 6. Electric circuits and fire control means for gun perforators 'are matters well known in the art and are not a part of this invention. 7 It will be seen that so long as explosion pressure is confined to the interior of the projectile there is no propulsive force acting thereon. When the pressure reaches a maximum, shear plate 5 is suddenly sheared from rim I8 along grooves l9a and lb thereby releasing explosion pressure into the barrel bore where it instantly becomes efiective to propel the projectile along and out of the gun bore with great force.

In gun perforators heretofore one of the difliculties encountered has been the necessarily short barrel. By exploding the charge inside of the projectile, I am enabled to utilize a gun having no explosion chamber and thereby materially increase the length of the barrel bore. It will also be seen that the invention herein disclosed by me further compensates for the short barrel by providing means whereby explosion pressure is first built up to'a maximum value inside the projectile and thensuddenly released into the barrel bore. Explosion pressure acting laterally inside of the projectile tends to expand shell 4 bore wall thereby creating an efiective seal against pressure leakage and further increasing the efficiency of the projectile.

Referring to the initial pressure retarding and subsequent high pressure releasing member 5-I8, by forming the grooves i9a and I9b therein the pressure effected shearing action is greatly facilitated once a pressure sufiicientto initiate shearing is reached. The result is an extremely sudden release of pressure into the gun barrel.

Referring to Fig. 3 another form of the projectile of my invention is shown. In this form the explosive receiving shell 4 is shown with the end 23 integral therewith. As in Fig. 2 igniter wire 6 is attached to the shell preferably by solder thereby grounding one end of the same. Connection to the other end being made by conductor 1 passing through insulating bushing 25. The numeral 24 designates a circumferential groove. With this projectile in place in the gun barrel bore the shell resists initial explosive pressure. At some subsequent high pressure end 23 is sundered from shell body 4 and thehigh pressure ,built up inside of the projectile is suddenly released within the gun bore rearwardly of the projectile. Groove 24 locates the place of break or rupture and ensures that the whole end 23 will be blown off thus permitting the full forceof the previously built up high pressure inside of the projectile to become immediately effective in propelling the projectile along and out of the gun bore.

It will be seen by Way of example that a plane rupturable or breakable plate could be used in place of the improved pressure delaying member r disclosed by me also that the rupturable part could be made integral with the explosive receiving shell. Therefore, I desire it to be understood that no limitations upon the invention are intended other than those imposed by the scope of the appended claims.

I claim:

1. A projectile for a gun casing perforator comprising a penetrating end, a rupturable explosive pressure resistant member and an intervening connecting tubular-portion adapted to receive a charge of explosive, said projectile being of substantiallyuniform diameter throughout its length rearwardly from said penetrating end.

2. A projectile for a gun type casing perforator providing an integral closed explosive receiving chamber of substantially uniform diameter throughout its length, said chamber being resistant to initial explosive pressure rupturable by subsequent high pressure 3. A projectile for a casing perforator of the gun type providing a cylindric explosive chamber of substantially uniform diameter throughout its length, and means closing said chamber resistant to initial explosive pressure whereby a propulsive pressure for-the projectile is built up in said chamber.-

4. A projectile for gun perforators providing an integral closed, rupturable explosive'chamber of cylindric uniformness and rupturable means resistant to initial explosive pressure whereby the release of pressure from said projectile chamber into said gun bore is delayed and a propulsive force for the projectile is thereby built up in said projectile chamber.

5. A projectile for gun perforators providing an integral closed explosive chamber of substantially uniform outside diameter, the wallet said chamber incorporating shearable means resistant to initial explosive pressure.

6. A projectile for gun perforators positioned in a gun bore providing an explosive chamber of cylindric uniformness and initial pressure resistant means closing said chamber, said means comprising a member constructed with a portion thereof shearable from said member by ap plied pressure for the purpose of suddenly releasing built up pressure in said projectile chamber into said gun bore to discharge the projectile.

7. An explosive pressure resistantshear plate for gun type perforator projectiles characterized by an outer rim-like portion attached to an inner portion by a decreased thickness of metal, said inner portion being shearable from said rim by applied pressure.

8. A. shear plate for gun type perforator projectiles providing a groove, said plate being shearable along said groove by explosive pressure.

9. A shear plate for a gun perforator projectile having formed in each of its two faces a groove, said grooves defining an inner portion resistant to initial explosive pressure and shearable from said plate by subsequent high pressure.

10. In a gun perforator for well casing, a barrel body providing a bore, a counterbore at the muzzle end and electrical contact means at the breech end thereof, a projectile disposed in said bore providing an explosive receiving chamber and electrical firing means, a piercable sealing member retained in said counterbore bearing against the projectile and thereby ensuring an electrical connection between said firing means and contact means.

11. A gun type casing perforator projectile positioned in a gun barrel bore having a penetrating end and rearwardly thereof a closed explosive receiving chamber of substantially uniform outside diameter, said chamber providing means resistant to initial explosive pressure and rupturable by subsequent high pressure whereby a high explosive pressure is first built up in said projectile chamber and subsequently released into said bore rearwardly of the projectile, and electrical igniting means for a charge of explosivein said projectile chamber.

12. A projectile for casing perforators of the gun type providing a penetrating end and rearwardly therefrom a closed cylindric explosive receiving chamber, said chamber having formed in its wall a circumferential groove and being otherwise of substantially uniform diameter throughout its length, said chamber being resistant to initial explosive pressure and separable at said groove by subsequent high pressure.

13. A projectile for a gun casing perforator having a cylindric explosive receiving chamber. a penetrating end secured to and closing one end of said chamber, explosive pressure resistant means of substantially the same diameter as, and, closing the other end of, said chamber, said chamber providing means intermediate and securing together its two ends resistant to initial explosive pressure andrupturable by subsequent high pressure.

14. In a projectile for a gun type casing perforator, a tubular explosive receiving chamber, penetrating means closing one end of said chamber and substantially integral therewith, explosive pressure resistant means closing the other end of said chamber and means securing together said two ends resistant to initial explosive pressure and rupturable by subsequent high pressure, the rupturing thereof effecting the sunderance of said chamber ends, said ends furthermore being of substantially the same diameter.

C. C. COLE. 

